ABU DHABI (Reuters) – Former U.S. president George W. Bush accused Russia on Thursday of meddling in the U.S. 2016 presidential election, calling Russian President Vladimir Putin a “brilliant tactician”.

Bush, interviewed on stage at a business conference in the capital of the United Arab Emirates, said there was clear evidence that the Russians had meddled but whether that affected the outcome of the election was another question.

“But they meddled and that is dangerous for democracy,” he said, adding that Russia had done the same thing during the Cold War and was adept at trying to manipulate opinion in the United States and Europe.

“Putin is a brilliant tactician who has the capacity to detect weakness and exploit it,” Bush said.

The Kremlin has repeatedly denied accusations by U.S. intelligence officials and others of interfering in foreign elections, including the 2016 U.S. vote.

In an apparent criticism of the immigration policies U.S. President Donald Trump, Bush called for changes in U.S. immigration rules, saying it was important to recognize that the United States had a history of welcoming people regardless of their religion or where they were born.

“Our system is broken but we’ve got to fix it. I had tried, but unsuccessfully,” he said without naming Trump.

“It is important for our economy and also important for our soul that the immigration system functions well.”

On Mexico, he said: ”I view it as a relationship vital for our economy and for our stability. We’ve got to enforce our borders and we’ve got to enforce our laws.

“There are people willing to do jobs Americans won’t do. A lot of Americans don’t like picking cotton at 105 degrees. But there are people who want to put food on their family’s table and are willing to do that.”